One of the most significant developments in the field of liquid applications, including paints and other protective coatings, is the introduction and development of aerosolized coatings, most commonly referred to as an “aerosol can” or “spray paint.” Retail stores have shelf upon shelf of these pre-filled pressurized containers filled with all sorts of liquids, from bug spray to sun screen formulations. In particular, a significant amount of shelf space is devoted to numerous complete paint and coatings formulations, in every imaginable color and gloss that are “ready to use.” These complete, pre-packaged spray paint containers provide the customer with a convenient means to purchase moderate quantities of paint in a readily useable spray container for easy application. Unfortunately, in situations where the end user only wants a small quantity of liquid or perhaps a custom blend of liquid ingredients or has a particular color in mind or wants to match a particular existing color, the current art of aerosols or spray paint forces the end user to accept only what is available or to select a paint color that in most cases is not the exact color that the user desires. This is because there is no convenient means to allow a consumer to prepare a custom liquid formulation for spraying or to select an exact match of color at the point of aerosol purchase. Instead, in the case of paint applications, the user must search a myriad of brands of spray paint in the hope of finding a color that at least comes close to the desired color. Often times, this causes the end user to travel from store to store in search of such a match. Another drawback of the conventional spray paint product is that the inability to prepare a final paint color at the point of sale directly affects the retailer. Because conventional spray paint is only available from the manufacturer in pre-selected and predetermined colors and gloss, the retailer is forced to stock and carry inventory for a large number of cans to accommodate a large number of colors and gloss finishes. This further requires the use of an inordinate amount of shelf space in the store, thus limiting the amount of other products that can be displayed.
A convenient solution to the above-mentioned problems would be to allow the retail outlet at the point of sale to prepare custom liquid formulations while the customer waits or to formulate a final color of an aerosol spray paint based on the end user's selections of color and gloss at the moment of sale. In this way, only a very limited number of containers with base liquids or containers with either a clear or neutral base paint formulation need to be stocked and shelved by the retailer. The end user can then have a custom blend a particular liquid formulation prepared or in the case of paint, select a final paint formulation that exactly matches his or her needs. My earlier U.S. Pat. Nos. 7,201,191 and 7,252,119 do provide one possible solution to the above-mentioned problems. However, there exists the problem, once the final liquid formulation is chosen and added to a container, of injecting or adding an appropriate propellant that is needed to create an atomized spray of the liquid for application to a substrate.
My invention now provides a new and improved liquid spray system that includes a disposable charge can that adds propellant and other compounds to a base liquid contained in a disposable container fabricated of low cost materials, such as, plastic, tin, or aluminum.